Motor brake



"Ma 26, 1925. 1,539,1fi6

A. DEWANDRE MOTOR BRAKE Filed Jan. 12. 1924 t/Bui d? fl/jerf 2e wenire l/Zorn e so quirements;

1 Patented May 26,1925.

u'lil'rso STAT ES:

L I mm nnwlmnmor LIEGE VBEQLGIUM- no'ron. 3am I I I to-which it appertains to make and use the same, reference being had to the accompany- .ing'drawings, and to letters or figures of reference marked therein, which form a part of this specification. p p I "The present inventionfrelates 'tof an improved suction brake for vehicles equipped with internal combustion engines, in which the braking action is produced by the partial vacuum created bythe suction of the 2' 0' engine. This partial vacuum acts on a pis- 'ton' workin 'in a cylinder which can be put;

in communication either with the atmosphere or with the suction pipe of the engine.

The object oftheinvention is to provide a brake of the character specified comprising a minimum number of parts whose operatlon is certain; thearrangement being such as to reduce to a minimum the. amount of air exhausted by the engine for the braking re- According to the invention, the valves for controlling the communication of .the brake i cylinder with the partial vacuum or with e atmosphere are regulated by a member 7 5' whose position depends upon the distance between the two parts of alost-motionconnec'tion located between the brake pedal or other brake-controlling -'element and the rodding.

40 -T his member operates thevalves inlsuch a way that the one which controls the communication ofthe cylinder with the atmosrphere is closed before the one which contro1s communication 5 opens.

with the suction "pipe The movements of the aforesaid. valvecontrollin' member can be effected b means of a flexi le shaft or cable ithe owden type which is connected atone end to the member in question and to' a fixed part of the apparatus, and at the other end to the Application filed January 12, 1924. Serial Nd. 685,814.

- the vehicle.

, ATENT OFFI elzlssusn two parts of the above-mentioned lost-mm constructional form of the improved motor brake, and k v Figure 2 illustrates diagrammatically a second constructional form thereof. 1

Referring first to Figure 1 the suction pipe 1 of the internal combustion engine (not shown) into which the duct 20 opens from the carburetor (not shown), is connected by a pipe 2 to a cylinder 3 in which works, a piston 4 the outer face of which is connected by a rod or cable 5 to a lever arm 6 com rised in the brake rodding A pipe opening into the atmosphere branches oil the pipe 2.

In the illustrated oonstructional'form a distributor-consistingof two valves 8 and .9 arranged respectively in the pipes 2 and 7, allows of placing the cylinder 3 in communication with the atmosphere or with the partial vacuum generated in the engine suction pipe .1 by

If communication with the atmosphere be cut Oil" by closing the valve 9, and 1f the the working of the engine of valve 8 bethen opened, the partial vacuum produced by the suction of the engine in the pipe 1 will be transmitted to the brake cylinder 3. i

-This partial vacuum will draw the piston T 3tow'ards the end of the cylinder in the direction of the arrow X, carrying along With it the cable-or rod 5 that is connected to the brake vrodding in such a manner as to thereby tproduce the braking operation.

I If at is moment the valve 8 be returned to its closed position, the .piston '3 theoreticalcupying, until communication with the atmosphere has been re-establ ished so as to allow the piston 3 to move back into its initial positionioppositely to the arrow X by the action o f returning springs. (not shown) ro'videdat any point of the brake installation. T I I For the purpose of co-ordinating the ly will remain in the position it is then oc- 30 3 upon the pedal 13 will first increase the distance between the two movably-relat'ed parts movements of the pistofi in the brake cylin-' der with the degree of braking force desired by the operator,thedistributor consisting of the two valves 8, .9 is controlled from the brake pedal 13 by means of a fork 10 connected to the said pedal by a member 12 here shown as a Bowden shaft. The two prongs of the fork act upon stops provided on the ends of the tail pieces of the valves 8,-9.

Springs 11 have a constant tendency to clos these valves. The lengths of the tail pieces of these valves are such as' to ensure that the valves shall act one after the other.

Considering first the position shown in Figure 1, it will be perceived that the valve 9 must be completely closed before the valve 8 begins to open, and vice versa.

It is also to be noted that the brake'pedal 13 is connected to the lever arm 6 by acoupling 14 comprising two elements ca-' pable of sliding relatively to each other in I such a manner when the pedal 13 is at the end of its stroke indicated by the arrow Y, that is to say, in the position in which the valve 8 is fully open, the said two elements of the coupling 14 will be in positive engagement with each other if the operator continuesto direction. I

In this arrangement, pressure exerted press the pedal 13 in the same 14 of the lost-motion connection which is locatedbetween the said pedal and the lever arm 6 ofthe brake rodding. The increase of this distance effects, through the intermediary of the Bowden shaft 12, a

decrease in the distance between the fork 10 and-a fixed point on the apparatus whereto 'is'attaclfed the end ofthe flexible sheath member of said shaft.

Consequently, the fork 1O iscaused to swing in a clockwise direction about its pivot, as a result whereof the valve 9 which controls communication between. the brake cylinder. 3. and. the atmosphere is first-of all closed. Thereafter,

- if the movement of the pedal has been sufli:

' to a slight extent, thus effecting the closingiciently great, the valve 8 opens and communication is established 'betweeg the brake cylinder and the suction plpe 1 of the en-' gm e,

er 3, and. the brake piston 4 moves A partial vacuum is thus set up in said cylin in the direction of the arrow X, thus exertingupon theroddin a force which tends to apply the brakes. t the same time, the

lever arm 6, moves in sucha way as to de'-.

crease; the distance between the two parts 14 of the lost-motion connection. As a. result,- the fork 10 moves counter-clockwise of valve 8; but under normal o ileratinlgi conditions,-thislast movement of t e 'for will not be continued tothe point where, valve- 9 is opened. Further depression of the pedal will have theefiect of again increasing the distance between the'two movably related arts 14, so that the fork 10 will open va ve 8, thus exerting a fresh braking forceupon the brakes.

It Wlll be apparent, in consequence, that each position of the pedal corresponds to a braking action of predetermined intensity.-

On the other hand, if the operator ermits the pedal to return toward its initial position, the distance between the two parts 14 decreases and the fork 10 moves counterclockwise, so that the valve 8 first closes and then valve 9 opens in turn and estabcylinder and the atmosphere, the result of which is to diminish the braking action.

The lever arm fi moves at the same time-so that the distance between the parts 14 tends to increase. As soon as this distance has,

reacheda predetermined extent, which will happen more or less rapidly according as the pedal has been moved back more or less, the valve 9 will close, thus cuttin' out communication between the brake ,c inder and the atmosphere.-

If the pedal is permittedzto move all the way back to its on inal position, the release of the brakes will e, complete and the .dis-' tance between the parts 14 will maintain its minimum extent so that valve 9 will remain open.

In order to of the partial vacuum acting in the cylinder 3, and with the object of enabling the piston 4 of the brake motor to be actuated when the engine of the vehicle is stopped, there intermediate rtservoir 17 (Fig. 2) interposed lishes communication between the brake establish a certain regularity v is provided according to this invention an between the suction pipe 1 and the pi e 2 leading to the cylinder 3. This interme 'ate with'an automatic valve 19.

What I claim is:

1. In a brake system for motorsfthe combination, with a suction pipe, and rodding of being placed in communication wit the suction pipe or with the atmosphere, a piston working therein and on which the engine suction acts to effect the braking o eration, closure members for controlling t ecomreservoir is fitted according to this invention for the brakes, of: a'brake cylinder ca able.

munication of the c linder with said pipe and with theatmos'p ere, a brake-o crating element, a lost-motlon connection tween said operating element and the brake-rodding embodying two movably-related parts, and a movable element for actuating said closure members operatively associated with said lost-motion connection so that its position depends upon the distance between the movably-related parts of said lost-motion connection. e

2. In a brake system jor motors, the combination, with a suction .pipe for the brakes, of; a brake cylinder capable of being placed in communication with the suction pipe or with the atmosphere, a piston working therein and. on which the engine suction acts to effect the braking operation, closure members for controlling the communication of the cylinder with said pipe and with the atmosphere, a brake-operating element, a lost-motion. connection between said operating element and the brakerodding embodyin two -movably-related parts, and amovab e element'for, actuating ,said closure members operatively associated withsaid lost-motion connection so that its position depends 11 11 the distance between the movably-relate parts thereof; said mov able element closing-the member which controls communication between the brake .0 1-1' inder and the atmosphere before it opens t e member controllin communication between said cylinder and t e suctlon pipe whensuch distance exceeds agiven extent.

and rodding' and with the atmosp I 3. Ina brake system for motors, the combination, with a suction pipe, and rodding for the brakes, of; a brake-cylinder capable of being'placed in communicationwith the suction pipe or'With the atmosphere, apiston working therein and on which the engine suctionacts to effect the braking operation, closure members for controlling the communication of the cylinder with said pipe ere, a brake-operatingelement, a lost-motion connection. between said operating element and the brake-rodding embodying two movably -related parts, a movable element for actuating said closure members, and a flexible connection between the closure-actuating element and the lostmotion connection embodying a wire attached at one end to one of the parts of said lost-motion connection and at the other end to said closure actuating. element, and a sheath encasing said wire and attached at one end to the other part of-said lost-motion connection and at the other end to "a fixed point on the apparatus.

in presence 0 two witnesses.

ALBERT DEWAND I tE.

In testimon whereof I aifix my signature Witnesses: t

Guonens Venom: Housman, Lnomnu LEVA. 

